Advances in semiconductor fabrication technology have enabled the creation of Micro Electro Mechanical (MEMS) devices capable of motion and applying a force at the micron level. MEMS devices having components and features sizes on the micron scale have been fabricated. Such MEMS devices may be employed in a variety of applications including, for example, electrical, fluidic, mechanical, and optical applications, and combinations thereof.
Disclosed herein are MEMS devices that include electromagnetic and other actuators for selectively generating displacement forces. The MEMS devices disclosed herein may be employed in many applications, including, for example, to generate displacement forces in electrical, fluidic, mechanical, and optical systems, and combinations thereof. In particular, the MEMS devices disclosed herein may be utilized to control electrical, optical, and electro-optical components in an optical fiber based system, such as an optical fiber communication system or an optical fiber computer system.
According to one exemplary embodiment disclosed herein, a MEMS device may include a substrate having a surface, an actuable element at least partially formed from the substrate, and an electromagnetic actuator disposed on the substrate for selectively applying a first force to the actuable element to displace the actuable element along a path. The actuable element may have a base and an arm coupled to the base. The base may include a portion comprised of a magnetic material. The electromagnetic actuator may comprise an electrically conductive coil, and the path of the actuable element may pass through a gap in the coil. The electromagnetic actuator may also comprise a magnetic core about which the electrically conductive coil may be wound.
According to another exemplary embodiment disclosed herein, a MEMS device may include a control mechanism operable to selectively apply a second force to the actuable element in a direction opposite to the first force. The control mechanism may be formed from the substrate. The control mechanism may be coupled to the actuable element at one end and to the substrate at another end. The control mechanism may include one or more stops, one or more clamps, one or more cantilevers, one or more springs, and one or more MEMS actuators.
According to another exemplary embodiment disclosed herein, a MEMS device may include a suspension mechanism for selectively controlling the location of the actuable element in a direction substantially perpendicular to the surface of the substrate. The suspension mechanism may include one or more clamps, one or more springs, or one or more cantilevers. The suspension mechanism may also include one or more permanent magnets or one or more electromagnets.
According to another exemplary embodiment disclosed herein, a MEMS device may comprise a substrate, an actuable element, an actuator disposed on the substrate for selectively applying a first force to the actuable element to displace the actuable element along a path, and at least one cantilever coupled to the actuable element at one end and coupled to the substrate at another end to control displacement of the actuable element along the path.
In one aspect, the actuable element may include an optical element for attenuating an optical beam lying in the path. The optical element may include a shutter for selectively blocking an optical beam. The shutter may include at least one of an opaque, a semi-transparent, a semi-reflective, and a reflective surface.
According to another exemplary embodiment disclosed herein, a method for fabricating a MEMS device on a substrate may include constructing an electromagnetic MEMS actuator on the surface of the substrate by building an electrically conductive coil on the surface of the substrate, the coil being arranged to form a gap between two ends of the coil, and forming an actuable element from a layer of the substrate at a position on the substrate to facilitate displacement of at least a portion of the actuable element relative to the gap upon activation of the electromagnetic MEMS actuator.
In one aspect, a method for fabricating a MEMS device on a substrate may further include constructing a cantilever on the substrate, the cantilever being coupled at one end to the substrate and at another end to the actuable element.
According to another exemplary embodiment disclosed herein, a method of fabricating a magnetically actuable MEMS component from a substrate may include applying and patterning a magnetic layer of the MEMS component on the substrate, applying and patterning a mask layer on the substrate to define a shape of the MEMS component, etching a top layer of the substrate in accordance with the mask to form the MEMS component, and releasing the MEMS component from the substrate to permit displacement of the MEMS component relative to the substrate.
In one aspect, applying and patterning a magnetic layer of the MEMS component on the substrate may comprise applying a layer of magnetic material to a top layer of the substrate, applying a layer of a first material to the layer of magnetic material to form a first mask layer over the layer of magnetic material, applying a layer of a second material to the first mask layer to form a second mask layer, patterning the second mask layer to form a first window through the second mask layer to the first mask layer, patterning the first mask layer through the first window to form a second window through the first layer to the layer of magnetic material, removing the second mask, patterning the layer of magnetic material through the second window to remove magnetic material exposed through the second window, and removing the first mask.
According to another exemplary embodiment, a method of fabricating a MEMS electromagnet on a substrate may include applying a lower layer of electrically conductive material to the substrate, patterning the lower layer to form a lower set of winding elements, applying a second layer of electrically conductive material over the lower set of winding elements, patterning the second layer to form connectors over the winding elements of the lower set of winding elements, and applying a third layer of electrically conductive material over the connectors, and patterning the third layer to form an upper set of winding elements that are electrically connected to the winding elements of the lower set of winding elements by the connectors.